I am being treated for colo-rectal cancer.
I had a big operation in December and I have a permanent colostomy. I had to have this as my tumour was low down in my rectum and it's not considered "safe" to do a mend with less than 3cm between removal and anus. Also as I am young (in bowel cancer terms, anyway ) they really did want to remove the whole lot to prevent recurrence of the cancer.
They will know by now where his cancer is, and which part of the colon needs removing. Mostly they can just remove a bit and stitch the rest back together. You often need a temporary colostomy for this. He can either look after this himself (I look after mine and in fact was not allowed to leave hospital until I had passed muster with the stoma care nurse) or a district nurse will come to look after him. If he is elderly he may well want a district nurse at the start anyway. As a "fit" 40 year old I obviously had different needs!
It is very easy to look after a stoma these days, particularly a colostomy. It obviously takes a bit of getting used to and you need to be determined that you will accept it and get on with things. All the bags are available on prescription. If he doesn't yet get free ones due to age he will do with a permanent stoma. There are some advantages . As a family you can all help by just assuming it is part of life and not getting worried about it.
You can find a lot more details on the cancerbackup website, or UK bowel cancer websites. I don't have the addresses for these at hand as have changed computer since I was diagnosed but one is something like "beatingbowelcancer.org.uk"
The bowel does not like being handled, so depending on his health and the severity of surgery, it may be a while before he is better again. My tummy was very distended for a long time and I became anaemic afterwards. I had really severe surgery and I was a lot better after seven weeks and pretty much myself before three months. You have to take care not to lift heavy objects for a while. He will lose weight initially.
He may also need chemotherapy or radiotherapy. Do you know about this yet?